sysfs, kernfs: introduce kernfs[_find_and]_get() and kernfs_put()
Introduce kernfs interface for finding, getting and putting
sysfs_dirents.
* sysfs_find_dirent() is renamed to kernfs_find_ns() and lockdep
assertion for sysfs_mutex is added.
* sysfs_get_dirent_ns() is renamed to kernfs_find_and_get().
* Macro inline dancing around __sysfs_get/put() are removed and
kernfs_get/put() are made proper functions implemented in
fs/sysfs/dir.c.
While the conversions are mostly equivalent, there's one difference -
kernfs_get() doesn't return the input param as its return value. This
change is intentional. While passing through the input increases
writability in some areas, it is unnecessary and has been shown to
cause confusion regarding how the last ref is handled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 105d09d..fd8f574 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -71,6 +71,11 @@
#ifdef CONFIG_SYSFS
+struct sysfs_dirent *kernfs_find_and_get_ns(struct sysfs_dirent *parent,
+ const char *name, const void *ns);
+void kernfs_get(struct sysfs_dirent *sd);
+void kernfs_put(struct sysfs_dirent *sd);
+
struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent,
const char *name, void *priv,
const void *ns);
@@ -95,6 +100,14 @@
#else /* CONFIG_SYSFS */
static inline struct sysfs_dirent *
+kernfs_find_and_get_ns(struct sysfs_dirent *parent, const char *name,
+ const void *ns)
+{ return NULL; }
+
+static inline void kernfs_get(struct sysfs_dirent *sd) { }
+static inline void kernfs_put(struct sysfs_dirent *sd) { }
+
+static inline struct sysfs_dirent *
kernfs_create_dir_ns(struct sysfs_dirent *parent, const char *name, void *priv,
const void *ns)
{ return ERR_PTR(-ENOSYS); }
@@ -133,6 +146,12 @@
#endif /* CONFIG_SYSFS */
static inline struct sysfs_dirent *
+kernfs_find_and_get(struct sysfs_dirent *sd, const char *name)
+{
+ return kernfs_find_and_get_ns(sd, name, NULL);
+}
+
+static inline struct sysfs_dirent *
kernfs_create_dir(struct sysfs_dirent *parent, const char *name, void *priv)
{
return kernfs_create_dir_ns(parent, name, priv, NULL);